package com.qying.tree;

public class ArrBinaryTreeDemo {

    public static void main(String[] args) {
        int arr[] = {1,2,3,4,5,6,7};

        ArrBinaryTree arrBinaryTree = new ArrBinaryTree(arr);
        arrBinaryTree.preOrder();
    }
}

class ArrBinaryTree{
    private int[] arr;

    public ArrBinaryTree(int[] arr) {
        this.arr = arr;
    }

    public void preOrder(){
        this.preOrder(0);
    }

    public void preOrder(int index){
        if (arr == null || arr.length == 0){
            System.out.println("数组为空,不能按照二叉树前序遍历");
        }

        if ((index*2+1)<arr.length){
            preOrder(2*index+1);
        }

        if ((index*2+2)<arr.length){
            preOrder(2*index+2);
        }
        System.out.println(arr[index]);
    }
}
